Abstract
Analytical CT reconstruction is popular in practice because of its computational efficiency, but it suffers from low reconstruction quality when an insufficient number of projections are used. To address this issue, this paper presents a new analytical method of backprojection Wiener deconvolution (BPWD). BPWD executes backprojection first, and then applies a Wiener deconvolution to the whole backprojected image. The Wiener filter is derived from a ramp filter, enabling the proposed approach to perform reconstruction and denoising simultaneously. The use of a filter after backprojection does not differentiate between real sampled projections and interpolated ones, introducing reconstruction errors. Therefore a weighted ramp filter was applied to increase the contribution of real sampled projections in the reconstruction, thus improving reconstruction quality. Experiments on synthetic data and real phase-contrast x-ray images showed that the proposed approach yields better reconstruction quality compared to the classical filtered backprojection (FBP) method, with comparable reconstruction speed.
Highlights
Reconstruction algorithms play an important role in Computed Tomographic (CT) imaging
Long synchrotron beamlines designed for phase-contrast X-ray imaging (PCXI) and CT, such as the Imaging and Medical Beamline (IMBL) at the Australian Synchrotron, all utilise a parallel geometry
For a real CT image with complex texture, the best reconstruction quality was achieved at α = 0.8 in both 60-projection and 480-projection reconstructions, and the proposed weighted filter contributed an improvement up to 1.47 dB and 2.13 dB gain, respectively
Summary
Reconstruction algorithms play an important role in Computed Tomographic (CT) imaging. Good reconstruction methods are required to yield high-quality CT slices, subsequently assisting practitioners and researchers to make better judgements, such as improved medical diagnoses. Reconstruction methods that are capable of generating high quality images with a small number of projections enable effective radiation dose reduction, which has significant benefits for human screening examinations, animal model research and for radiation sensitive samples [1]. Improvements in acquisition hardware have enabled the resolution of volumetric CT projection images to increase, allowing the fine-details of the internal structures of the target to be visualised. Phase contrast X-ray imaging setups at synchrotron facilities are capable of capturing high resolution images with pixel gaps of 10 μm [2], with more than 2000-by-2000 pixels.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
